1. Field of the Invention
The present invention is directed to the interface between the rubber-sealing boot of a control lever and the control lever knob.
2. Description of the Prior Art
In operating a work vehicle, such as a bulldozer, the operator controls a plurality of work operations through manipulating various control levers that position the hydraulic control valves. The hydraulic control valves in turn regulate the flow of pressurized hydraulic fluid to hydraulic cylinders that manipulate the bulldozer blade.
Typically, the control levers extend upwardly through a control console located in the operator""s cab. The control lever has an arm and a knob that is affixed to the arm. The arm is operatively coupled to a valve control linkage that regulates the hydraulic control valve in response to movement of the control lever. The operator grasps the knob of the control lever for manipulating the arm of the control lever.
The control console is provided with control apertures through which the control levers pass. These apertures are larger than the diameter of the control lever to allow for pivotal movement of the control lever. To prevent dust, dirt and debris from entering the control console, the control aperture may be covered by a rubber boot that engages the control lever and the edge of the control aperture. The boots can be coupled to the knob by a tongue and groove joint. A secondary fastener in the form of adhesive is used to bond the rubber boot to the knob.
It is an object of the present invention to provide a rubber boot/control knob interface that does not require a secondary fastener.
A control lever for a work vehicle extends upwardly through a control aperture in a control console. The control lever comprises an arm and a knob. One end of the arm is coupled to the control valve linkage for positioning the control valve. The other end of the arm is mounted to the knob. The knob is provided with a cylindrical shaft having a first groove and a second groove. The first and second grooves adjoin one another to form a tandem stepped groove. The first groove is deeper than the second groove having a smaller diameter. A rubber boot extends between the knob and the control console. The rubber boot has a circular control lever opening through which the control lever extends. The circular control lever opening is provided with an inwardly extending flange. The inwardly extending flange is received in the first groove. A downwardly extending foot extends from the inwardly extending flange and is received in the second groove. The inwardly extending flange and the foot are separated from one another by a step that corresponds to the radial differences between the first and second grooves.